popViewController解散模态VC Swift后

Question

我想在我解雇了一个popViewController后，再去做modalVC。但是，我的代码不起作用。怎么啦？

func showMessage(withTitle title: String, message: String) {

        let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)

        let alertAction = UIAlertAction(title: "ok", style: .default) { (_) in
            self.dismiss(animated: true) {
                self.navigationController?.popViewController(animated: true)
            }
        }
        
        alert.addAction(alertAction)
        
        present(alert, animated: true, completion: nil)
    }

我也尝试过这样做：

  let controller = ViewController()             
controller?.popViewController(animated: true)

Answer 1

我创建了两个视图控制器vc1和vc2。vc1有一个导航控制器，vc2被推到vc1之上，是导航堆栈。在vc2中，会显示警报，在单击ok按钮时，vc2被弹出并从导航堆栈中删除。对我来说很好。Vc1代码：

class ViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()
  self.navigationController?.pushViewController(storyboard?.instantiateViewController(withIdentifier: "SecViewController") as? SecViewController ?? SecViewController(), animated: true)
}
}

Vc2代码：

class SecViewController: UIViewController {

override func viewDidLoad() {
    super.viewDidLoad()

    showMessage(withTitle: "title", message: "Message")
}


func showMessage(withTitle title: String, message: String) {
    
    let alert = UIAlertController(title: title, message: message, preferredStyle: .alert)
    
    let alertAction = UIAlertAction(title: "ok", style: .default) { (_) in
        self.dismiss(animated: true) {
            self.navigationController?.popViewController(animated: true)
        }
    }
    
    alert.addAction(alertAction)
    
    present(alert, animated: true, completion: nil)
}